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171.
In this paper we explain how a shift from culture of the black tiger shrimp (Penaeus monodon) to the Pacific white shrimp (Litopenaeus vannamei) took place during 2002–6 in Thailand. We use system innovation theory to help explain how niche substitution led to a regime change within a Thai aquaculture industry trying to maintain international competitiveness but under pressures from a global landscape in which consumers are increasingly concerned with health and ecological sustainability. Support from a vertically integrated major firm, an extensive foundation of learning networks within the industry, and early profitability made the scaling-up and embedding of the experiment with white shrimp very rapid once the formal ban on import of exotic broodstock was lifted. Disease management with domesticated, specific pathogen-free strains of white shrimp has proven much easier than with black shrimp still dependent on capture of wild broodstock. Moreover relative production costs are lower. The switch in species had significant consequences for the environment and firms. Using life cycle analysis we found that rearing white shrimp requires less resource and produces less waste than black shrimp. The shift in regime, however, also made it more difficult for small farms and hatchery businesses.  相似文献   
172.
Municipal solid waste management (MSWM) in the United States is a system comprised of regulatory, administrative, market, technology, and social subcomponents, and can only be understood in the context of its historical evolution. American cities lacked organized public works for street cleaning, refuse collection, water treatment, and human waste removal until the early 1800s. Recurrent epidemics forced efforts to improve public health and the environment. The belief in anticontagionism led to the construction of water treatment and sewerage works during the nineteenth century, by sanitary engineers working for regional public health authorities. This infrastructure was capital intensive and required regional institutions to finance and administer it. By the time attention turned to solid waste management in the 1880s, funding was not available for a regional infrastructure. Thus, solid waste management was established as a local responsibility, centred on nearby municipal dumps. George Waring of New York City organized solid waste management around engineering unit operations; including street sweeping, refuse collection, transportation, resource recovery and disposal. This approach was adopted nationwide, and was managed by City Departments of Sanitation. Innovations such as the introduction of trucks, motorized street sweepers, incineration, and sanitary landfill were developed in the following decades. The Resource Conservation and Recovery Act of 1976 (RCRA), is the defining legislation for MSWM practice in America today. It forced the closure of open dumps nationwide, and required regional planning for MSWM. The closure of municipal dumps caused a 'garbage crisis' in the late 1980s and early 1990s. Private companies assumed an expanded role in MSWM through regional facilities that required the transportation of MSW across state lines. These transboundary movements of MSW created the issue of flow control, in which the US Supreme Court affirmed the protection of garbage under the Commerce Clause of the Constitution. Thus MSWM in America today is largely managed by municipalities, and operated by a relatively small number of private companies. It consists of a mixture of landfill, incineration, recycling, and composting, and is regulated under RCRA, the Clean Air Act and other related federal and state laws.  相似文献   
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The relationship between exposure to the World Trade Center (WTC) attacks, increased substance use, functional impairment and mental health service use, controlling for depression and post-traumatic stress disorder, was assessed through an in-school survey of directly exposed students (N = 1040) attending the five middle and five high schools nearest the WTC. The survey was conducted 18 months after the attacks. Students with one WTC exposure risk factor had a five-fold increase in substance use, while those with three or more exposure risks had a nearly 19-fold increase. Increased substance use was associated with impaired school work, school behaviour and grades. Students reporting increased substance use were nearly twice as likely to want help but were no more likely than asymptomatic students to receive services. Adolescents reporting increased substance use, without co-morbidity, were less likely to receive psychological services than others. Attention to the needs of substance-using adolescents exposed to disaster is needed.  相似文献   
175.
Chang FH  Wang HJ  Wang SL  Wang YC  Hsieh DP  Chang LW  Ko YC 《Chemosphere》2006,65(10):1723-1730
The soil metal contamination arising from the discharge of the high density of electroplating factories in the geographic center of Taiwan has prompted concern about human exposure to harmful metals. This study aimed to determine the levels of nickel (Ni) in urine of residents living in the high vs. low factory-density areas, and to examine how these levels relate to gender and age. A total of 660 subjects, resident in the area for the last five years, were sampled according to the stratified random sampling approach, at ages 35-44, 45-54, and 55-64years for both genders. Metals in urine samples were analyzed by inductively coupled plasma mass spectrometry (ICPMS). The geometric mean (95% confidence interval (CI)) of urinary Ni was 6.30 (5.99-6.62)mug/l. The 0.95 parametric reference interval (90% CI) of urinary Ni was estimated to be 1.74 (1.62-1.88) to 22.73 (21.14-24.44)mug/l. Subjects in the areas with a high density of electroplating factories had significantly higher urinary Ni levels than those in the low-density areas, but both types of areas had obviously higher urinary Ni levels when compared to the non-occupationally exposed population from western countries. The health significance of elevated urinary Ni and its causative factors remain to be determined.  相似文献   
176.
Disturbance to wintering birds by human recreational activities has become a major concern for managers of many natural areas. Few studies have examined how recreationists perceive their effects on birds, although this impacts their behavior on natural areas. We surveyed 312 users on two coastal ornithological sites in Brittany, France, to investigate their perception of the effects of human activities on wintering birds. The results show that the awareness of environmental issues and knowledge of bird disturbance depends on the socioeconomic characteristics of each user group, both between the two sites and within each site. Results also indicate that, whatever the site and the user group, the vast majority of the respondents (77.6 %) believed that their own presence had no adverse effects on the local bird population. Various arguments were put forward to justify the users’ own harmlessness. Objective information on recreationists’ awareness of environmental issues, and particularly on their own impact on birds, is important to guide managers in their choice of the most appropriate visitor educational programs. We recommend developing global but also specific educational information for each type of user to raise awareness of their own impact on birds.  相似文献   
177.
This work addresses the plasma treatment of two solid waste streams and production of fuel gases from the process. In this study, carpet waste and simulated solid wastes generated by a United States Air Force Basic Expeditionary Airfield Resources Base deployment were used. Waste was treated in a furnace fitted with a 100kW plasma arc torch. The off gas was analyzed to determine its composition. The product gas was composed primarily of carbon monoxide and hydrogen, with small amounts of methane, benzene and toluene also detected. These experiments demonstrate the feasibility of producing fuel gases by plasma treatment of the solid waste streams. While the thermal energy value of the fuel gas produced in these experiments was less than the energy input, a higher waste-to-fuel gas conversion efficiency is expected in full-scale application.  相似文献   
178.
The paper focuses on the example of a local island community in Greece, to illustrate the difficulties of effective consensus building, in support of sustainable policies. In the first section the issue of sustainability and the importance of participation are discussed, before moving to a brief outline of the nature of participation and its sources since the 1960s. It follows an analysis of the epistemological framework of consensus building process which is considered as the most integrated and sophisticated version of participatory planning. This analysis serves as a background for judging the appropriateness of consensus building for the resolution of an environmental problem harassing a Greek island community. It is about the problem of water availability and management in the small Aegean island of Leros. The paper shows how illegal practices in the use of water, administrative fragmentation and confusion over knowledge of the problem and its solutions lead to divisions in the stakeholder groups and to obstacles in the way of participation. The intrinsic problems embedded in Greek (and probably not alone) society and political culture, which prevent collective action and participation, account in part for the anticipated risk of unwelcome, illegitimate outcomes of a potential consensus building process. Nevertheless, if communicative planning is to gain universal acceptance, it should first resolve some critical theoretical and practical shortcomings related to its normative, ethical and philosophical assumptions. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   
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